Csharp Shell 自定义渲染器重置 TabBarUnselectedColor 设置的 colored颜色

我有一个.Net Maui应用程序，它使用Shell TabBar:

<TabBar>
    <Tab Title="Home" Icon="{StaticResource IconHome}">
        <ShellContent ContentTemplate="{DataTemplate local:MainPage}" />
    </Tab>
    <Tab Title="Coverage&#10;Calculator" Icon="{StaticResource IconCalculator}" >
        <ShellContent ContentTemplate="{DataTemplate calculator:CoverageCalculatorPage}" />
    </Tab>
    <Tab Title="Distributor&#10;Locator" Icon="{StaticResource IconLocator}">
        <ShellContent ContentTemplate="{DataTemplate locator:DistributorsLocatorPage}" />
    </Tab>
    <Tab Title="Scan&#10;QR Code" Icon="{StaticResource IconQrScanner}">
        <ShellContent ContentTemplate="{DataTemplate qrScanner:QrScannerPage}" />
    </Tab>        
    <Tab Title="More" Icon="{StaticResource IconMore}">
        <ShellContent ContentTemplate="{DataTemplate more:MoreFeaturesPage}" />
    </Tab>
</TabBar>

图标 colored颜色 在Styles.xaml中设置如下:

        <Setter Property="Shell.TabBarUnselectedColor" Value="{AppThemeBinding Light={StaticResource LaticreteColor}, Dark={StaticResource LaticreteColor}}" />

下面是选项卡栏的外观:

因为我的标签需要多行文本，所以我为Android应用了一个定制的呈现器:

internal class LaticreteShellRenderer : ShellRenderer
{
    public LaticreteShellRenderer(Context context) : base(context) { }
    protected override IShellBottomNavViewAppearanceTracker CreateBottomNavViewAppearanceTracker(ShellItem shellItem)
    {
        return new LaticreteTabLayout();
    }
    public class LaticreteTabLayout : Java.Lang.Object, IShellBottomNavViewAppearanceTracker
    {
        public void ResetAppearance(BottomNavigationView bottomView)
        {
            throw new NotImplementedException();
        }

        public override void SetAppearance(BottomNavigationView bottomView, IShellAppearanceElement appearance)
        {
            bottomView.SetMinimumHeight(180);

            var bottomNavView = bottomView.GetChildAt(0) as BottomNavigationMenuView;

            for (int i = 0; i < bottomNavView.ChildCount; i++)
            {
                var item = bottomNavView.GetChildAt(i) as BottomNavigationItemView;
                var itemTitle = item.GetChildAt(1);
                TextView smallTextView = (TextView)((BaselineLayout)itemTitle).GetChildAt(0);
                TextView largeTextView = (TextView)((BaselineLayout)itemTitle).GetChildAt(1);
                smallTextView.SetLines(2);
                largeTextView.SetLines(2);
            }
        }

这将重置选项卡的 colored颜色 :

我发现我可以这样更改自定义渲染器中的文本 colored颜色 :

                    smallTextView.SetTextColor(global::Android.Graphics.Color.Brown);
                largeTextView.SetTextColor(global::Android.Graphics.Color.Brown);

但我仍然不知道如何设置图标 colored颜色 ，以及如何在App.xaml或Colors.xaml中引用我的自定义 colored颜色 集.

请告知为什么重置选项卡栏未 Select 的 colored颜色 ，以及如何修复此问题.